Brain Neoplasms General Considerations 1 Comprise 10 of

Brain Neoplasms: General Considerations 1. Comprise: 10% of all tumors 2. Most common childhood neoplasms 3. Peak incidence at 5 th decade 4. Supratentorial tumors in adults 5. Infratentorial tumors in childhood

Brain Neoplasms: General Considerations 6. Different tumors in different ages 7. Primary tumors infiltrative, metastatic well-demarcated 8. Intraneural seeding occur, but no extraneural metastasis 9. Produce neurologic symptoms by size, location, invasiveness, and secondary effects

Varieties of brain tumors n n n n n Meninges: meningioma, hemangiopericytoma Astrocytes: astrocytoma (various types) Oligodendrocytes: oligodendroglioma Ventricles: ependymoma, choroid plexus papilloma, colloid cyst Vascular: hemangioblastoma Primitive cells: germinoma, medulloblastoma, neuroblastoma, pineoblastoma, retinoblastoma Neuronal: ganglioma, gangliocytoma Pituitary: adenoma, craniopharyngioma Nerves: schwannoma, neuroblastoma

Incidence of Intracranial Gliomas (All ages) Glioblastomas 55. 0% Astrocytomas 20. 5% Ependymomas 6. 0% Medulloblastomas 6. 0% Oligodendrogliomas 5. 0% Choroid plexus papillomas 2. 0% Colloid cysts 2. 0%

Incidence of Primary Intraspinal Intramedullary Gliomas Ependymomas 63. 0% Astrocytomas (grades 1 and 2) 24. 5% Glioblastomas (Astrocytomas grades 3 and 4) 7. 5% Oligodendrogliomas 3. 0% Other tumors 2. 0%

Frequent brain tumors n n n n Meningioma Astrocytoma/glioblastoma Oligodendroglioma Ependymoma Medulloblastoma Schwannoma/neurofibroma Phakomatosis

Meningioma Arachnoid cells origin Attached to dura, subdural Common sites Changes in cranium Hyperostosis Invasion Microscopic: whorls and psammoma bodies

Gliomas n n n Astrocytes- astrocytomas – Fibrillary – Pilocytic Oligodendrocytes- oligodendrogliomas Ependyma- ependymomas

Astrocytomas Adults: Supratentorial Solid Malignant Childhood: Infratentorial Cystic Benign

Adult vs childhood astrocytomas n n Adult: fibrillary. Grading varies from low grade malignancy to one of most malignant brain tumor. Childhood: pilocytic. Very low grade tumor (benign).

Fibrillary astrocytomas n n Grossly solid Common in cerebral hemispheres Low grade in young, higher grade in older Grading – astrocytoma (low grade) – Anaplastic astocytoma – glioblastoma multiforme

Fibrillary astrocytoma: microscopic n n n Low grade- hypercellularity, pleomorphism Anaplastic- as above plus mitosis, vascular endothelial proliferation Glioblastoma multiforme- as above plus necrosis and pseudopalisades. Grossly variegated appearance (multiforme)

Pilocytic astrocytoma n n n Common in childhood Most slow growing of the gliomas Sites: cerebellum, around III V. , optic nerve Grossly cystic with mural nodule Microscopic – elongated hair-like (pilo) elongated cells – Rosenthal fibers

Rosenthal fiber definition n n Dense, eosinophilic fibers within cytoplasmic processes of astrocytes. Correspond to aggregate accumulation of intermediate filaments in these processes.

Oligodendroglioma Slow growing tumor Potentially malignant Calcifications

Tumors in Ventricles 1. Ependyma: Ependymoma 2. Choroid Plexus: Papilloma

Ependymomas n n n Arise from ependymal lining- ventricles and central canal of spinal cord Common in childhood 4 th V. common in cerebrum Most common tumor of spinal cord parenchyma in adult Microscopic – perivascular pseudorosettes – ependymal rosettes

Primitive neuroectodermal tumors n n Neuroblastoma- cerebral hemispheres Medulloblastoma- cerebellum Ependymoblastoma- ventricles Pineoblastoma- pineal region

Medulloblastoma n n n Origin: primitive neuroectodermal cells Age: 1 st decade of life Site: vermis of cerebellum May cause hydrocephalus Subarachnoid dissemination

Histologic patterns: definitions n n n Whorls: onion-skinning pattern of tumor cells Psammoma bodies: laminated calcium Pseudopalisading: lining up of the tumor cells around a central necrotic area Palisade: lining up of tumor cells around their own cytoplasmic processes. No necrosis. Pseudorosette: tumor cells around blood vessels, cells equidistant from vessel walls. Rosettes: tumor cells around central lumen or fibrillary area of cellular processes

Brain Tumors: Microscopic Meningioma Whorls and psammoma bodies Glioblastoma Pseudopalisades Oligodendroglioma Mosaic/poached-egg Ependymoma Perivascular pseudorosettes Medulloblastoma Rosettes

Tumors of Nerve Roots and Peripheral Nerves 1. Schwannoma viii Cranial nerve (Acoustic sch. ) Spinal roots, posterior Peripheral nerves 2. Neurofibroma Spinal Roots, rare Peripheral nerves 3. Malignant variants Rare

Peripheral nerve tumors n n n Schwannoma Schwann cells Compress the nerve trunk Encapsulated Easily resectable without nerve damage Microscopic: – Antony A and B fibers – Verocay bodies n n n Neurofibroma Schwann cells, neurites, fibroblasts Fusiform and involves nerve trunk Not encapsulated Not resectable without sacrificing nerve Micro- Intermingled cells with wavy nuclei

Metastatic brain tumors n n n n Most common brain tumor in adults. Common primary sites: melanoma, lung, breast, GI tract, kidney. Most are in cerebrum (MCA territory). In gray-white junctions due to rich capillarity Discrete, globoid, sharply demarcated tumors. Amenable to surgical resection. Single or multiple. Brain edema frequent.

Phakomatosis: definition n Phakos (Greek): lentil mole or freckle. Neurologic abnormalities combined with defects of skin or retina, explained by their common ectodermal origin. Involvement of visceral organs

Phakomatosis (Neurocutaneous dysplasia) 1. Neurofibromatosis (von Recklinghausen's dis. ) 2. Tuberous Sclerosis 3. Sturge-Weber disease (Encephalofacial Angiomatosis) 4. von Hippel-Lindau Disease 5. Neurocutaneous Melanosis

Neurofibromatosis 1. Dominant inheritance 2. Multiple neurofibromas Central - CNS peripheral nerves 3. Increased incidence of: meningioma glioma schwannoma - bilateral VIII N. 4. Cafe-au-lait (melanosis) in skin 5. Elephantiasis: increased connective tissue

Tuberous Sclerosis 1. Dominant inheritance 2. Clinical triad: seizures mental retardation adenoma sebaceum 3. Retinal hamartoma (phakoma) 4. Tubers in cerebral cortex 5. Subependymal giant cell astrocytoma 6. Hamartomas in other organs: heart, kidney

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